[jira] [Resolved] (IGNITE-6877) Improve behaviour for non-correlated subqueries
[ https://issues.apache.org/jira/browse/IGNITE-6877?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Vladimir Ozerov resolved IGNITE-6877. - Resolution: Won't Fix (was: Fixed) > Improve behaviour for non-correlated subqueries > --- > > Key: IGNITE-6877 > URL: https://issues.apache.org/jira/browse/IGNITE-6877 > Project: Ignite > Issue Type: Improvement > Components: sql >Affects Versions: 2.3 >Reporter: Alin Andrei Corodescu >Priority: Minor > > Ignite behaves poorly in terms of performance when given queries which > contain IN or = operators followed by a non-correlated subquery. My guess is > that the query is actually run for each row of the table in order to test the > condition. > A possible solution is to store the results of the subquery in a temporary > table, and use it from there. > A workaround at the moment is to use joins instead of IN or = operators, but > this makes the query much more complicated. > Example: > SELECT name > FROM Employees > WHERE age IN (SELECT age FROM Customers) > The performance of this query is very slow for small amounts of data (about > 20 seconds for 4000 rows in each table last time I tried) -- This message was sent by Atlassian JIRA (v7.6.3#76005)
[jira] [Resolved] (IGNITE-6877) Improve behaviour for non-correlated subqueries
[ https://issues.apache.org/jira/browse/IGNITE-6877?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Vladimir Ozerov resolved IGNITE-6877. - Resolution: Fixed Closing due to long inactivity. Planned logic is to be redesigned soon, so tickets will be created as needed. > Improve behaviour for non-correlated subqueries > --- > > Key: IGNITE-6877 > URL: https://issues.apache.org/jira/browse/IGNITE-6877 > Project: Ignite > Issue Type: Improvement > Components: sql >Affects Versions: 2.3 >Reporter: Alin Andrei Corodescu >Priority: Minor > > Ignite behaves poorly in terms of performance when given queries which > contain IN or = operators followed by a non-correlated subquery. My guess is > that the query is actually run for each row of the table in order to test the > condition. > A possible solution is to store the results of the subquery in a temporary > table, and use it from there. > A workaround at the moment is to use joins instead of IN or = operators, but > this makes the query much more complicated. > Example: > SELECT name > FROM Employees > WHERE age IN (SELECT age FROM Customers) > The performance of this query is very slow for small amounts of data (about > 20 seconds for 4000 rows in each table last time I tried) -- This message was sent by Atlassian JIRA (v7.6.3#76005)
